Device for feeding envelope blanks



Oct. 25, 1966 E. H. TREFF DEVICE FOR FEEDING ENVELOPE BLANKS 5 Sheets-Sheet 1 Filed June 8, 1964 INVENTOR. 5 2/1 5076. FREQ- Oct. 25, 1966 TREFF 3,281,142

DEVICE FOR FEEDING ENVELOPE BLANKS Filed June 8, 1964 5 Sheets-Sheet 2 INVENTOR. [P/VE'ST H 72 5;;

BY wi M2 ATTORNE Y5 Oct. 25, 1966 E. H. TREFF 3,231,142

DEVICE FOR FEEDING ENVELOPE BLANKS Filed June 8, 1964 5 Sheets-Sheet 5 INVENTOR. [Qt [f7 A ZZEFF ORNEYS IER Oct. 25, 1966 E H. TREFF DEVICE FOR FEEDING ENVELOPE BLANKS 5 Sheets-Sheet 4 Filed June 8, 1964 s VIII/III].

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DEVICE FOR FEEDING ENVELOPE BLANKS Filed June 8, 1964 5 Sheets-Sheet 5 'Wum! I INVENTOR. [A /v55;- H/ZFFF' 974% WAZQZ ATTORNEYS United States Patent 3,281,142 DEVICE FOR FEEDING ENVELOPE BLANKS ErnestI-I. Tref'f, PortWashington, N.Y., assignor to F. L. Smithe Machine Company, Inc, New York,'N.Y., a corporation of New York Filed June 8, 1964, Ser. No. 373,436 '9 Claims. (Cl. 271-2) The present invention relates in general to mechanisms for feeding envelope blanks one at a time from the bottom of a stack of blanks. More particularly the invention relates to an improvement in feeders such as disclosed in US. Patent No. 2,954,225, issued September'27, 1960, for Feeding Mechanism for Envelopes and the like.

In the high speed operation of feeders such as described in Patent 2,954,225 particularly with light weight paper stock such as employed in air mail envelopes, a common problem is that the oscillating picker or sucker arm will malfunction and transfer two or more envelope blanks at the same time from the bottom of the stack. The present invention concerns an improved sheet feeder which will reliably transfer only the bottommost sheet from a stack of sheets even though they may be of light weight tissue stock. The present invention also concerns an improved sheet feeder for very smooth papers which due to their smoothness tend to adhere to one another as they are fed.

In accordance with the invention, the feeding mechanism includes an oscillating sucker arm having a concave end portion adapted to separate the leading edge of a bottommost envelope blank in a stack of envelope blanks. A reciprocating separator blade operates in conjunction with the oscillating sucker arm to support the leading edge of the stack of blanks as the lowermost blank is removed. The separator blade includes timed means for supplying a blast of air at the plane of the blade to flutter the edges of the blanks adqacent the lowermost blank to alleviate their tendency to be sucked downwardly with the lower most blank onto the surface of the sucker arm. The suction applied through the sucker arm and the pressurized air blast of the separator blade are interrupted by suitable valving means in timed cooperative relationship so that successive lowermost blanks of the stack are transferred individually to the surface of an adjacent rotating drum.

A particularly novel aspect of the invention resides in the fact that the air blast emitted from the separator blade, while it is supporting the bottommost envelope blank of the stack, positively transfers a portion of the bottommost envelope to the surface of the sucker arm. At the same time the air blast is effective to flutter the edges of the envelopes above the bottommost envelope to prevent them from also being transferred with the lower envelope to the surface of the sucker arm. With the edge of the bottom envelope thus preconditioned, the rapid downward movement of the sucker arm, occurring after withdrawal of the separator blade, is effective to transfer the leading edge of the bottom blank only to the surface of an associated conveyor means.

It is an object of the present invention to provide an improved feeding mechanism for envelope blanks and the like.

It is another object of the present invention to provide in a feeding mechanism for envelope blanks and the like improved means for removing the bottom blank from "ice a stack of envelope blanks and transferring the same to an associated conveyor.

Another object of the invention is to provide a novel separator blade having means for directing a pressurized fluid against the edges of the sheet material supported thereon.

Another object of the invention is to provide novel means for the partial transfer of the bottom blank to the surface ofthe sucker arm prior to withdrawal of the separator blade.

Another object of the invention is to provide a novel method for the transfer of envelope blanks one-by-one from the bottom of a stack of blanks to the surface of an oscillating sucker arm.

For other objects and a better understanding of this invention, reference may be had to the following detailed description taken in connection with the accompanying drawings in which:

FIG. 1 is a fragmentary side elevation view showing the stack feeder portion of an illustrative envelope mak ing embodying the invention;

'FIG. 1A' is a fragmentary view of a portion of the feeder mechanism shown in FIG. 1 with the separator blade in the retracted position;

FIG. 2 is a top plan view taken along line 2-2 of FIG. 1;

FIG. 3 is a cross sectional view taken along line 3 3 of FIG. 2';

FIG. 4 is an enlarged sectional view of the separator blade shown in FIG. 3;

FIG. 5 is a cross sectional view taken along line 55 of FIG. 3;

FIG. 6 is a cross sectional view taken along line 6--6 of FIG. 5;

FIG. 7 is a sectional view of a portion of the separator blade and associated apparatus shown in a retracted position;

FIG. 8 is an exploded perspective view of the parts which channel the air blast to the separator blade;

FIG. 9' is an enlarged view of the separator blade looking in the direction of the arrows 99'of FIG. '6;

FIG. 10 is a fragmentary view partially in section showing the sucker arm just prior to start of its downward movement engaging the lowermost blank of the stack and the separator blade, with the air blast on, inserted between the lowermost blank and the adjacent blank;

FIG. 11, is a section taken along line 1111 of FIG. 10; t 7

FIG. 12 is a fragmentary view partially in section similar to that shown in FIG. 10 but showing the parts at a somewhat more advanced stage in the operating cycle;

' 1G. 13 is "a section taken along line 1313 of FIG. 12;

FIG. 14 is a view similar to FIG. 12 but showing the sucker arm after its return to the position of FIG. 10;

FIG. 15 is a section taken along line 1515 of FIG. 14 showing in greater detail the partial transfer of the new lowermost blank to the surface of the sucker arm;

FIG. 16i's a viewsimilar to FIG. 14 but showing the parts at a further stage in the operating cycle;

FIG. 17 is a section taken 'along line 1717 of FIG. 16; and i FIG. 18 is a fragmentary plan of FIG. 14.

Referring in particular to the drawings, wherein similar view along line 1$18 reference numerals identify corresponding parts throughout the several views, It represents the feeding mechanism for an envelope making machine (not shown). While the invention has particular utility in combination with envelope making machines, it should be appreciated that the invention has general utility wherever individual feeding of sheets is required.

The device of the present invention is designed to feed envelope blanks 12, having a body portion 14, end flaps 16, a bottom flap 18, and a seal flap 20 as seen more clearly in FIG. 2, one at a time from the bottom of a stack 22 of the envelope blanks. As seen in FIG. 1, the stack 22 of envelopes 12 is inclined slightly to the vertical.

Stack 22 rests mainly upon a pair of conventional rotary supporting and separating discs 24, 24 which are carried and driven by their respective shafts 26 in timed relationship to the remainder of the feed mechanism. Each of these discs has at least one opening 28 for the passage of a blank from the top of the disc to the bottom thereof. The marginal edge of seal flap 20 of the lowermost envelope in the stack 22 rests upon a supporting roller 30. A reciprocating separator blade unit generally designated 32 when in the stack engaging position acts as a support for the bottom flaps 18 at the forward end of the stack. A blade 33, having a recessed portion 35, forms the forward part of the blade unit, the blade having a shoulder 37 upon which the stack rests. An oscillating cup-shaped sucker arm assembly 34 operates in timed conjunction with the separator blade to remove the lowermost blank from the stack. The separator blade and sucker arm assembly move periodically into and out of.supporting relation with the stack at the lower margin of the bottom flap 18 of the lowermost blank. A supporting U shaped finger 36 extends slightly into the forward portion of stack 22 to take the weight of most of the bottom fiaps off the separator blade and sucker arm. The blanks resting on the finger 36 slip downward past the finger as the underlying blanks are progressively withdrawn.

Before describing the blank feeding mechanism in detail, the principal parts will be briefly referred to, and the mode of operation outlined.

Referring now to the stage in the cycle of operation of the feeding mechanism as represented by FIGS. and

11, the separator blade unit 32 is located in stack supporting position and sucker arm assembly 34 is about to move downwardly away from the stack to transfer the leading edge of the bottom blank to an associated conveyor. A plurality of air blast ports 38 serve to allow the passage therethrough of a stream of air in the direction indicated by the arrows in FIGS. 10, 12, and 14. Suction ports 40 in the concave face 42 of sucker arm 34 provide the passages through which a suction is produced to pull the lowermost blank from the stack flush up against the concave face. The air blast through ports 38 serve to assist in separating the lowermost blank from those above it. The separating air blast is advantageous, particularly where thin paper tissue and high speed blank removal are utilized, because some air is sucked through the minute pores in the blank pulled onto the concave face of the sucker arm unit. Thus the blank above the lowermost one may also be sucked downwardly resulting in an undesirable double blank separation from the stack. While the air blast above described finds particular utility in the rapid feeding of tissue paper stock, it is equally beneficial in the feeding of very smooth papers which may or may not be of a porous nature. With smooth papers the individual sheets lie in such intimate contact that it is difficult for air to enter between them in the event that the first sheet is rapidly withdrawn. This is a condition similar to that observed between two gauge blocks where, when wrung together, they seem to stick as though held by a large attractive force. The air blast, therefore, pre-conditions successive blanks to make it 4 easy for air to enter during the instant that the lowermost blank is rapidly pulled away. Therefore, regardless of the type of paper being fed, the novel air blast feature of the invention will serve to eliminate the vacuum generated during feeding between the first and second sheets.

FIGS. 12 and 13 illustrate a succeeding step in the cycle of operation of the unit. Thus, the sucker arm unit 34 has moved downwardly pulling the bottommost blank along with it. Simultaneously, disc 24 which rotates in timed relationship with the sucker arm and separator blade has rotated to allow the end flaps to pass through openings 28 and permit the bottommost blank to break away from the stack. Separator blade unit 32, at this point is still in the stack supporting position.

FIGS. 14 and 15 show the start of the cycle for feeding the next and newly presented bottommost blank. Thus, sucker arm unit 34 is shown after it has just returned upwardly to a position adjacent the new bottommost blank in the stack. The stream of air from ports 38, assist the suction in the passages 40 in separating the bottommost blank from the remaining blanks, to flutter and hold back the sheet above the bottommost sheet to thereby positively separate the lowermost sheet from the sheet just above it, as best seen in FIG. 15.

This air blast first stage separation of the bottom blanks positively transfers a portion of the blank to the surface 42 of sucker 34 (see FIG. 15). This first stage transfer may be better appreciated by reference to FIG. 18 wherein the area of the concave face 42 is shown substantially greater than the area of the tip of blade 33. In this way a generally crescent shaped contact by the blank is made with the face 42. It is noted that were it not for this positive separation of the sheets, particularly in instances where the blanks are composed of thin tissue paper, the suction in passageways 40 would pull the sheet above the bottommost sheet down also, as explained above. At this point the tip of separator blade 33 still supports the lowermost blank and separator disc 24 has rotated to the point where it again supports the end flaps of the bottommost blank. Recess 35 allows the edge of the lowermost blank nearest the ports 38 to be pushed downwardly by the air blast. The recess also aids in fluttering the edges of the blanks.

In the final step illustrated by FIGS. 16 and 17, the separator blade unit 34 has been withdrawn from beneath the stack 22 and the air blast has been turned off. The air blast is shut off at this point so that it will not blow the sheet above the bottom sheet onto the bottommost sheet which is being pulled away by the sucker arm unit. In this step the outer peripherial upper edge 43 of the sucker arm serves to support the stack 22 of envelope blanks 12, as best seen in FIG. 17.

As each blank is pulled downwardly by the sucker arm unit 34, it is fed to a feed drum 44 located directly beneath the stack 22 and secured to a drive shaft 46. Oscillating means, deflector 51, such as disclosed in Patent No. 2,954,225, referred to above serve to transfer the envelope blank from suction arm unit 34 to the rotating drum 44 and its associated feed belts 48. The feed belt 48 runs in a groove 50 in drum 44. A pair of guide arms 52 are cooperative with the outer surface of the belts 48 to convey the blanks one by one to an associated mechanism such as an envelope making machine.

A suction timing control 54 is provided to turn the vacuum in passageways 40 off prior to the transfer of the envelope blank from the sucker arm unit to drum 44 and on again as the sucker arm unit returns upwardly to engage the lowermost envelope blank in stack 22. The suction control 54 controls the timing of the vacuum applied to the ports 40 which communicate through conduit 58 with the interior of shaft 76. The conduit 58 of the oscillating sucker arm unit 34 in turn communicates with a nozzle 64 which provides a fluid passage to ports 40 in surface 42.

The oscillating sucker arm unit 34 and the reciprocating separator blade unit 32 are driven from a shaft 68 (FIG. 3) which is rotated at a predetermined rate of revolution. A sucker arm channel cam 70 is aflixed to shaft 68. A cam follower 72 is connected to a crank 74 which in turn is connected to a tubular rock shaft 76. A bolt 82 is provided to tightly secure block 60 and the arm unit 34 to the rock shaft 76. Channel 78 in which follower 72 rides is of a varying radius. Thus as shaft 68 turns cam 70, crank 74 is oscillated thereby pivoting sucker arm unit 34 with rock shaft 76. Nozzle 64, therefore, is moved toward and then away from stack 22. The shaft 76 includes a central passageway 80. Passageway 80 communicates through an aperture 81 in the end of conduit 58 to direct the necessary vacuum to the ports 40.

A separator blade channel cam 84 also connected to shaft 68 acts through a follower 86 to operate a crank 88 which is mounted on shaft 90. A second crank 92 is secured to shaft 90 by a locking bolt 94. Crank 92 in turn is pivotally connected at its other end to a link 66. The link 66 is secured at its other end to a shaft 96 extending through an elongated slot 98 to a pivoted separator blade arm 100. Cam follower 86 is set in channel 102 which is of a varying radius to thereby provide the required reciprocating movement of separator blade unit 32 through pivot arm 100, shaft 96, link 66, crank 92, and crank 88. The cam and cam followers for the sucker arm unit and separator blade unit are adjusted to provide the required timed relationship therebetween as described above.

An air blast connection nipple 104 communicates with passage 106 in fixedly mounted block 108 as best seen in FIGS. 5-8. A cylindrically shaped member 110 fits within a bore 112 in block 108. Aperture 114 communicates with passage 106 when member 110 is inserted within passage 112. A disc shaped washer 116 of a suitable low friction plastic or the like is aflixed as by adhesive to one end of member 110, the flange being placed adjacent and in slideable contact with surface 118 of the separator blade pivot arm 100.

Pivot arm 100 includes a U shaped upper portion 120 pivotally mounted upon shaft 122 to a suitable portion of the machine frame 123. As stated hereinabove, the link 66 of the sucker arm is secured to shaft 96 held in place by a nut 124 which passes through the mid-portion 126 of pivot arm 100. The lower portion 128 of pivot arm 100 includes a passage 130 which communicates with chamber 132 which in turn communicates with air blast ports 38, as best seen in FIGS. 6 and 9. Passageway 134 is fluidly connected through aperture 114 to passage 134 in flange 116.

Turning now to FIG. 6, it can be seen that when the lower portion 128 is in the solid line position, passageways 130 and 134 are in registry to provide the required path for the passage of air from an air source tube 135 through nipple 104, passages 106, 134, 130 to chamber 132 and thence through ports 38. In the solid line position blade 33 of separator blade unit 32 is in its forward position underlying stack 22. However, when the reciprocating separator blade unit is Withdrawn to thereby withdraw the blade 33 from beneath the stack of envelope blanks, lower portion 128 of pivot arm 100 slides in the direction indicated in FIGS. 6 and 7 to the dotted line position wherein passageway 130 is moved out of registry with passageway 134. Thus, in the retracted position the path for air flow is cut otf thereby cutting off the air blast to ports 38.

I have described what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the following claims.

What is claimed is:

1. A blank feeder for envelope making machines adapted to withdraw envelope blanks one by one from the bottom ofa stack comprising, in combination, means for supporting and separating the lowermost blank from a stackof envelope blanks and periodically directing an air blast at the lower part of the stack of envelope blanks, a feed cylinder disposed beneath the stack in position to receive the envelope blanks, an oscillatably mounted sucker'arm including a sucker end portion, means for periodically applying suction. to said sucker arm to engage the bottom flap margins of successive bottommost blanks of the stack, and means for oscillating the sucker arm between the stack and said feed cylinder to engage each blank in succession and move it into proximity to said feed cylinder, said supporting and separating means including a reciprocating separator blade unit, said blade unit including a blade portion having a blank engaging tip of small total area relative to the surface area of said sucker end portion, said blade unit having formed therein passage means rearwardly of said blade portion for directing an air-blast at predetermined intervals in the plane of the blade portion against the edges of the bottommost blanks of said slacks of blanks.

2. A blank feeder as in claim 1 including a pair of separator discs each having at least one opening for the passage of a blank therethrough from the top of the disc to the bottom thereof, said discs constituting the principal support for the stack of blanks and means for rotating the discs.

3. A blank feeder for envelope making machines as in claim 1 wherein said means for oscillating the sucker arm includes a rotary cam having a channel of varying radius, a cam follower that rides in the channel and a crank connected to said cam follower which aids in transmitting the motion of the cam follower to the sucker arm.

4. A blank feeder for envelope making machines as in claim 1 wherein said blade has formed therein a recessed portion between said tip portion and said passage means.

5. A blank feeder for envelope making machines as in claim 1 wherein said supporting and separating means includes a rotary cam having a channel of varying radius, a cam follower that rides in the channel and a crank connected to said cam follower which aids in transmitting the motion of the cam follower to the separator blade unit.

6. A blank feeder adapted to with-draw blanks of sheet material from the bottom of a stack of blanks and forward the blanks, one by one, to an associated conveying means, comprising, separator blade means for supporting a lower edge of said stack of blanks, and arm means cooperative with said blade means to assist in supporting a lower edge of said stack of blanks and for removing one blank at a time from the bottom of said stack of blanks and transferring the blanks so removed to the associated conveyor means; said arm means including, a concave end portion having a plurality of spaced suction passages therein terminating in said concave end portion, and means for applying suction to said passages; said separator blade means including, a blade portion having a blank engaging tip of small total area relative to the surface area of said concave end portion so that portions of the bottommost blank surrounding said tip are transferred to the surface of the concave end portion prior to withdrawal of said blade portion from below the bottom edge of the stack of blanks, further including means for directing air under pressure in the plane of said blade portion against the edges of the bottom blanks in said stack to thereby flutter the edges of said blanks and to positively separate the lowermost blank from the adjacent blanks and transfer it to the concave surface of the arm means end portion surrounding said tip, said air directing means comprising a plurality of air ports formed in said blade portion rearwardly of said tip portion.

7. Apparatus according to claim 6, including means for withdrawing said blade means from its blank supporting position.

8. Apparatus according to claim 7, including control Valve means for interrupting the air pressure directing means as the blade means is withdrawn from its stack supporting position.

9. A blank feeder for envelope making machines as claimed in claim 1, wherein said passage means consists of a plurality of air ports.

References Cited by the Examiner ROBERT B. REEVES, Primary Examiner.

STANLEY H. TOLLBERG, Examiner. 

1. A BLANK FEEDER FOR ENVELOPE MAKING MACHINES ADAPTED TO WITHDRAW ENVELOPE BLANKS ONE BY ONE FROM THE BOTTOM OF A STACK COMPRISING, IN COMBINATION, MEANS FOR SUPPORTING AND SEPARATING THE LOWERMOST BLANK FROM A STACK OF ENVELOPE BLANKS AND PERIODICALLY DIRECTING AN AIR BLAST AT THE LOWER PART OF THE STACK OF ENVELOPE BLANKS, A FEED CYLINDER DISPOSED BENEATH THE STACK IN POSITION TO RECEIVE THE ENVELOPE BLANKS, AN OSCILLATABLY MOUNTED SUCKER ARM INCLUDING A SUCKER END PORTION, MEANS FOR PERIODICALLY APPLYING SUCTION TO SAID SUCKER ARM TO ENGAGE THE BOTTOM FLAP MARGINS OF SUCCESSIVE BOTTOMMOST BLANKS OF THE STACK, AND MEANS FOR OSCILLATING THE SUCKER ARM BETWEEN THE STACK AND SAID FEED CYLINDER TO ENGAGE EACH BLANK IN SUCCESSION AND MOVE IT INTO PROXIMITY TO SAID FEED CYLINDER, SAID SUPPORTING AND SEPARATING MEANS 